The present invention relates to a method for splitting an optical signal and, more particularly, splitting the optical signal into a number of electrical signals having lower bit rates than the optical signal.
Signals with high data rates over 40 Gbits/s can, at present, not yet be processed electrically. Demultiplex circuits are therefore used, which split such signals into a number of sub-signals with lower bit rates.
Known demultiplex circuits use an optical pulse source such as, for example, an optical voltage controlled oscillator, abbreviated as VCO, in conjunction with optical logic circuits, which often utilize non-linear effects in optical waveguides. In this process every nth bit is selected from the incoming signal.
Another option involves using a VCO with electro-optical transformers triggered by it such as, for example, electro-absorption modulators, abbreviated as EAM, or Mach-Zehner modulators, abbreviated as MZM. In this process too every nth bit is selected from the incoming signal.
Both arrangements have the disadvantage that they are relatively complex in structure and expensive. These arrangements are also polarization-dependent. Also a stable structure is necessary, in particular from a thermal point of view, to avoid runtime drifts, which cause bit errors.